1. Field of the Invention
This invention relates to thrust friction bearings constituted of laminate material which has a substrate or carrier layer and a friction slide layer, and has at least one holding lug that is integrally formed and is bent substantially orthogonally to the slide layer surface. The invention also relates to methods for making such thrust slide bearings.
2. Description of the Related Art Including Information Disclosed under 37 CFR .sctn..sctn.1.97-1.99
For the locking of thrust friction bearings against rotation, particularly in automatic transmissions, holding lugs are used on the bearing elements. These may be disposed at the inside of a bearing washer, at the outside diameter thereof, or even within the bearing surface. Due to the high degree of bending and the considerable forces which are applied when shaping the holding lugs, peeling of and damage to the friction bearing material occurs, with fissuration or even detachment of friction material. If such a material particle becomes detached during operation of the bearing, the proper functioning of the entire group of components is imperiled. For this reason, holding lugs cannot be accepted as satisfactory on certain thrust friction bearings which have disadvantageous dimensions or material combinations.
From German Patent Publication 26 38 996 K-flange bearings are known, which are provided at the inner circumferences with the above-described holding lugs, bent in the direction of the bearing axis and braced against or locked to the bearing bore. Measures for preventing the material damage above referred to, however, are not indicated nor are they an object of this known invention.
From German Patent Publication 16 25 626 there are known collar friction bearings consisting of a metallic support body and running (slide) layers of plastic, where before the collar is pressed on, it is provided with axial slits for the formation of lobes or lugs. The lobes of the collar are not themselves machined additionally to prevent any material damage in bending.
German Patent 726,897 describes a method for making a collar-bearing shell half with a steel support or carrier shell and a slide-metal layer. Secured to the running or slide surface and to the collar is a flat steel strip having flanges, which latter are plated with a poured-on bronze layer. After the orthogonal bending of the flanges, the steel strip is then bent to a semicylindrical form. Before the bending of the flanges, the flange-bending areas are bordered on both sides at their edges by grooves extending in the longitudinal direction of the sheetmetal. Since the grooves do not lie in the bend region but instead in the flat portions of the bearing shell half and of the collar, a peeling or lifting-off of portions of the slide layer occurs in the bend region.